cupped front tire - heavier springs?

Ok, so my front tires start to get cupped at about 1500 miles and I can't figure out why. There is no cupping on the rear. I'm thinking, but not sure that my weight is doing it. I'm 6-2 and weight about 240ish...I'm a fatty. I'm thinking it's from cornering. Do I need to install heavier springs in the forks? I've got the oem springs almost all the way for stiffness as it is. It handles great and it doesn't pogo when stopping or anything, just shortens my front tire life.

I should mention that it has done this equally with 207's, 208's and now my newish qualifiers are starting to do it.

I don't know but there's a bump for ya.

What tire preasure do you run?

you're almost 100 lbs over what the stock spring rate can handle. but before doing all this, check to make sure that your suspension is evenly adjusted on each side.

I run 38-40 psi rear
and 33-34 psi front

The suspension settings are equal on both sides too - L/R. I also try to keep weight distribution 40/60 front/rear when cornering hard and what not and the cupping is equal on the left and right side of the front tire. Like I said, handling is good and the front doesn't dive in corners. Should I look into the heavier springs and what should I go with? And why doesn't the rear get cupped? Thanks

rear tire doesn't get cupped as when you're leaning, it doesn't move, but the front tire is leaned and turned opposite way of turning direction.

i would recommend ohlins springs for the front as their spring rates are pretty on for the rated weight...if you go racetech, you should go up.

quote:

ORIGINAL: Tahoe SC


i would recommend ohlins springs for the front as their spring rates are pretty on for the rated weight...if you go racetech, you should go up.

You mean if I go with the ohlins to get the exact weight or close but if I go racetech that I should go heavier? Are they not as strong?

it's not about strength of the spring but more about the spring rate rating.
racetech's rating is just a bit 'off'. just be aware if you do go racetech.

also, if you do repring, technically you should revalve too. check around, a decent spring and vavle should cost like 4 bills...includes new springs, fork oil, labor, revalving (using existing parts), etc...this will be good enough for some track and twists...

for all track and twists, the cost goes up...comes to like 600-700 bucks to well over 1K...to even higher.

only place that i would recommend is one local to me...and that's www.ppsracing.com not beacause it's the best but because they are great and they are local. guys further south and north than i am use other local places.

as for the rear...i would try and find an ohlins replacement or see if a suspension shop can resrping it and revalve it to your weight, or revalve as close as possible to your weight.

total bling for front and rear to get it good enough should be like 6-7 bills.

Maybe these questions should be posted elsewhere, but it bears on this discussion.
1) What exactly is cupping?
2) I'm 205 and have stock suspension. I've been on track once (plan to do it again soon) and don't "think" I need aftermarket suspension. Why would a person like me want to spend 4-700 bucks on m/c parts when I don't race? I don't have any handling problems at this point, my speed/ skill is not to the point to manifest deficiencies in the equipment.

quote:

ORIGINAL: Jaybird180

Maybe these questions should be posted elsewhere, but it bears on this discussion.
1) What exactly is cupping?
2) I'm 205 and have stock suspension. I've been on track once (plan to do it again soon) and don't "think" I need aftermarket suspension. Why would a person like me want to spend 4-700 bucks on m/c parts when I don't race? I don't have any handling problems at this point, my speed/ skill is not to the point to manifest deficiencies in the equipment.

Cupping is when the tire wears. The leading edge next to a tread groove dips down and the trailing edge next to the following tread groove remians where it's supposed to. If you run your hand on the tire one way it feels smooth, rubbing the other way it feels sharp at the treads. kinda hard to explain.
I'm going to have to agree with your number 2 posting also. Mine handles just fine for my abilities and don't want to spend that much dough on it. If it was to be a bonifide track bike I probably would, but I can't ride it to it's potential safely on the road. If it was a lot easier and cheaper fix ie just springs, I would do it.
Thanks Tahoe for all your input - I'll go on a diet, it's easier to fund

Well Tahoe, I think you know a little about my riding goals. I'd be willing to consider new springs if I knew it was right for me. I don't even know if my sag is set properly (I don't have a buddy that's into the techie stuff).

When I rode on the track, I didn't have any wheelspin, but I did notice that after the apex the power was so strong that I felt my back snap. I did feel the rear squat a bit and I recall something else when adding power that wasn't smooth. Never felt it on the street.

Man, I'm feeling that urge to get back on the track again. Dammmit, I don't wanna be a track addict. I haven't ridden on the street since my trackday. I don't even know if it will be fun. All I think about is riding on that track again. The score is Track: 2 Me: 2

cupping...forget the why it happens and how, etc...

when your front tire looks just jacked...not even rounded anymore, but like a nuked hot dog with all these bumps everywhere...it's cupped mang!

now why would you want to upgrade suspension? because if you're serious about riding or getting good, you will be at the limits of the stock suspension in no time, based on your weight.

on track or at twists, suspension is one of the most important thing...

imagine this...your suspension is too soft...so every turn you dive into, the suspension compresses all the way...can't take anymore...so what takes the remaining load? the front tire...until it can't take no more and the tire washes out.

ok...now imagine this...as you turn you lean the bike over...and as the suspension compresses, the amount of lean you have to get the bike through the corner decreases as compression in your suspension increases...

just like a lowered bike has less cornering clearance than a non-lowered one.
does that make any sense?

it's something that you'll want to look into eventually though...

I don't think I experienced the front suspension bottming. I did experience something in the rear, but keep in mind that i don't believe my preload to be set correctly.

Yes I do want to get better and I've read MUCH about suspension being the best upgrade for a bike. As I plan to keep my F4i for another 2 seasons, I probably will do it, but after my 1st track outing, I'm just about convinced that I haven't come even close to the capabilities of the stock setup.

And yes, my front tire lookes boogered on the right side. Summit JC is mostly a right hand course.

maybe not enough rebound or tire pressure

i weight 205 and when i used to have stock springs when i went into a tight corner the front would dive down make you feel like your driving into the ground, now with .85 racetech springs i can't make the front dive down that much in any way.the bike stays in about the same angle all the time.once you have ridden a bike that is set up right for your weight you never be able to go back to stock.thats why i have such a hard time want to trade up to a bigger bike because i know i will have to work the bugs out of it and believe me it takes a long time to do it.ride adjust/ ride adjust.

Maybe I need more experience to be able to feel what you're saying. Although I know my front dives under hard braking, I could confidently trailbrake into Turns 1 and 2 at Summit Pt JC.

i mostly noticed in very tight turns say maybe a 5 mph turn taken at 30 maybe where you come in, break real hard, lay your bike over and fast as you can. as you are breaking from maybe 50 to 30 in a few short feet as you let go of the break to turn it felt like the front wanted to nose into the ground.Now with the right springs I cn take same corner and the bike stays at mosly the sme angle.

shouldn't be doing trail braking yet mang...should be busting nice and smooth...trail braking is good when you need to get past other riders and what not but if you want to be fast, smooth with great lines is the way to go...then when you have someone who you just can't get past...then go in hot, go in hard, brake harder and slam that bike through...but riding like this with bad suspension = washing out the front.

Maybe I'm not trail braking...maybe it's just a comfort thing to continue to stay on the brake a little bit while turning in. First time I did it, I felt like I was too fast (for me at least). I noticed how smooth the chasis was, no on/off up/down front end bobble.

Hmmmm.....Are you saying that better setup suspension would eliminate up/down bobble? My front end doesn't po-go, but I've been on bikes that do, very scary stuff.

pogo? i think that means your suspension isn't doing what it's supposed to do...it should just absorb it and quickly dampen it, but if you're like pogo-ing like a 60s cadillac...then you need to stiffen that sucker up!

as far as holding the brake while in the turn, experienced riders use it to scrub off some speed when they know they will be entering a turn hot...but doing so puts more strain on the front tire (potential wash out situation) and will require more rider input to get the bike leaning and keep it leaning. if you grab the brake in a turn, the bike will want to stand itself upright.

jaymang...i would recommend that you not do that anymore...but just get your timing good, so you ride like 'water'...ahhahah

Ok, I will work on not doing that. I don't do it on the street, it just felt "right" on the track. I understand what you mean about the timing. I brake while downshifting and then turn-in while just a bit on the brakes. I hit the apex while coming off the brakes. I see my exit and the feed the gas.

I should be Brake/ Downshift; Off Brake, let chasis settle and set speed; wait until turning point; turn; gas and go
Is that what you mean by timing?
That should allow me to practice smoothness too, right?

whats up, so i havent experienced anything like bottoming out my front shocks in turns but i am a heavy guy too, i weigh bout 235-240 i am loosing weight but till then should i change my stock setting on my suspension, i really dont wanna mess with it unless i really should since suspension aint the kinda thing i wanna screw up on and find out in a turn, so basically even tho i am heavier than the stock setting is setup for should i change it if i aint bttoming out my suspension

oh and jaybird where is new carollton at, you near towson area at all?

Read: http://www.sportrider.com/tech/suspension/

At your weight the suspension is not doing it's job. You need to set your sag for YOU, then work on the damping settings.

oh mang jay you hurt my head reading your ritual...hahahah...yea but basically yes...make you smooth...

try this next time you hit the twists, select a gear that can take you through all of it...like 2nd...3rd if it's mostly sweepers...stay with this one gear...through it...and guess what...NO BRAKES!

they do this in some riding schools...that will get you working on entering the turn at just the right speed and make you SMOOTH as my arse after i loofa it.